or certain professionals (physicians being the most significant example). Breach of such oaths is normally conceived of as being governed by public law procedures, or disciplinary proceedings by the relevant society or professional body, rather than through a civil law action for breach of promise, the requisite conditions for which would often not be met in the circumstances of breach of the oath. Though such examples of modern oath-making therefore describe a much reduced field in which the oath is used, the matters in which the swearing of oaths continues to be used all have legal significance. Lawyers cannot thus ignore the function and consequences of the oath, albeit the private law consequences of a breach of oath tend to be less significant than the public law ones.

(c)  Threats

Threats, if seriously made rather than as boastful attempts to coerce others, share the similarity with promises that they both declare a commitment by the speaker to perform some future act which will affect the hearer of the statement. The distinction lies in the fact that the promisor commits to a future beneficial act in favour of the party to whom the promise is addressed, while the maker of a threat commits himself to some act harmful to the party to whom the threat is directed.98 As the late scholastic Lessius put it in his definition of a promise, a promise ‘concerns something that is good’.99

This distinction is an important one: as threats, unlike promises, do not disclose virtuous intent, they are not looked upon favourably by the law. On the contrary, they may give rise to negative consequences for the maker of the threat, who may, by making the threat, have committed a criminal act, or, in a contractual setting, may be deemed to have committed an anticipatory breach of contract if, for instance, the threat is not to perform a contractual obligation when it falls due. Threats are, from a legal perspective, not susceptible to actions of enforcement by the party to whom they are addressed should the maker of the threat not perform the

98Páll Árdal provides a different definition of a threat, as a commitment to act which is unwelcome to the hearer: see Árdal, ‘And That’s a Promise’, 231. Thus, on Árdal’s view, a threat may be constituted by something unwelcome to the hearer even though the promised act is objectively of benefit to him, such as a threat issued to a child to correct its bad behaviour. This alternative definition provides an uncertain distinction between promises and threats, as the distinction can only be determined once the subjective attitude of the hearer of the statement is discovered. For that reason, the objective definition of a threat given in this text is suggested as preferable.

99Lessius, De iustitia et jure, 2.18.1.

threatened act: a court will not compel a harmful act by a private person. However threats are treated, they are not to be considered promises under the definition proposed earlier.

Promise thus shares with contract the feature that there must exist, at the time the obligation is constituted, an intention on the part of the debtor to protect or improve the other party’s interests (even if that is not the effect which they in fact produce),100 and thus to undertake something which is of benefit to that other party. This distinguishes voluntary obligations from involuntary or imposed obligations: in tort/delict, unjustified enrichment and negotiorum gestio, the party upon whom the duty is imposed is required to remedy a worsening of the other’s position.

(d)  Donation (gift)

A further act which can be distinguished from a promise is that of donation/gift (the two terms are synonymous).101 Promise and donation are sometimes equated on the basis that the intention of the party undertaking each act is that another is benefited by the act, and also that a promise may be, and a donation is, made on account of the liberality of the party undertaking the act, that is out of a motive of generosity.102 However, donation and promise may be distinguished in that:

(1)a promise may or may not be gratuitous; donation, per contra, is by nature a gratuitous act,103 and

100Promises or contracts may unintentionally worsen the other party’s position, if changing circumstances have rendered the originally intended benefit harmful to the other party’s interests, but this does not prevent the promise or contract from having being validly constituted.

101This topic is discussed further in Hogg, ‘Promise: The Neglected Obligation’, and at greater length in Hogg, ‘Promise and Donation in Louisiana and Comparative Law’.

102D. 39.5.1: ‘A person makes a donation … for no other reason than to display his liberality and munificence.’

103Though in some systems, a transaction may be partly donative, and partly remunerative, and still count as donative; see also the DCFR, Art. IV.H-1:202. Non-gratuitous receipts of benefits are likely to give rise to a legal inference that the transferor should receive something for the transfer, whether by virtue of the obligation of contract, unjustified enrichment, or negotiorum gestio. Such an inference can be countered by demonstrating that the transfer was made for reason of liberality on the part of the transferor. Even where the transfer is made out of liberality, and thus a donation, it is sometimes maintained that the transferee owes at least a counter-duty of gratitude, and that if this is not forthcoming the donation may be revoked. This was a rule of Roman law, and was adopted in some civilian and mixed systems, such as Scotland (see Stair I.8.2) and Louisiana (where ingratitude is given a very restricted meaning: CC Art. 1557).

(future) services to B’. For present legal purposes, however, references to donation will be restricted to a transfer of property rights. On that basis, a so-called donation of future services by A to B should in fact be described as a promise by A to B of future services and not as a donation.107

(e)  Warranties (guarantees)

It is important to recognise that the word warranty may be used in a number­ of different senses. In English law, for instance, the word has been used to refer variously to a term of a contract, as opposed to a mere representation; to a term not going to the root of a contract, as opposed to one that does (a condition), so that its breach only gives rise to a right to damages but not to terminate the contract; or to a statement of fact held out (‘guaranteed’) as true (sometimes annexed to or contained within a contract, sometimes issued separately to a contract, as in a so-called ‘collateral warranty’).108 It is in this last sense that the term is meant here, a sense in which the term ‘guarantee’ is often used synonymously.

Some commentators have characterised promise sufficiently widely to include a warranty as a type of promise,109 but much depends on the definition adopted for both a promise and a warranty. A definition of a promise was offered earlier, and a warranty has just been defined as a statement by which a party holds out that something is the case, that is, that a state of facts exists at the time of the making of the statement (or existed at a previously stated time). Examples might include statements such as ‘I warrant that the pollution which affected this land has been cleaned up’ or ‘I warrant that these goods have been owned since manufacture by one party alone’. The distinction with a promise, as defined earlier, will be obvious: a warranty thus defined would not appear, on the face of it, to commit the maker of the statement to any future action. However, that is not the end of the matter, as a breach of the warranty, in the sense that the statement is found not to have been true when made, would normally be expected to give rise to remedies on the part of the person to whom the warranty was made, remedies which would oblige the party in breach to do something (for instance, pay damages). Such remedies might be seen as arising by operation of law, and thus not to be characterised as promissory, or they

107A useful comparison of donation and promise, from the perspective of various European legal systems, may be found in Schmidt-Kessel, Principles of European Law: Donation.

108In Finnegan v. Allen [1943] 1 KB 425, 430, the term warranty was said to be ‘one of the most ill-used expressions in the legal dictionary’.

109See Atiyah, Promises, Morals and Law, p. 161.

might be seen as arising voluntarily, as an implied consequence of the warranty itself, and thus properly characterised as a conditional promise implicit in the statement of warranty itself. The ‘voluntary but implicit’ characterisation seems, however, a somewhat strained one, and the analysis underlying it would seem to suggest that all contractual remedies imposed by courts should be classified as voluntary and promissory in nature, which is not commonly held to be the case.

Where the maker of a warranty expressly binds himself to a future conditional act if the warranty is untrue, and thus the warranty is conceived of more extensively, then the totality of the statement is more easily classifiable as a promise, or at least as containing a promise. Consider, for instance, the statement

‘I warrant that this land is clean of all pollution; if it is not, then I undertake to effect such cleaning or to pay damages.’

If one were to call the whole of this statement the warranty, then the warranty­ so defined would incorporate both a statement of fact as well as a promise; on the other hand, if the statement were to be conceived of as breaking down into a warranty (the statement of fact) followed by a promise (conditional on the warranty being untrue), then the warranty and the promise would be distinguishable, though a promise would certainly be present.

What the above discussion shows is that whether one should classify a warranty as a promise or as something else depends first on whether warranties are defined narrowly or broadly. The narrowly defined warranty – the mere statement of fact – is, on one view, not a promise, as it contains no undertaking to do anything. On another view, however, even such a simple statement of fact ought to be seen as containing an implicit duty to do something, such as pay damages, if the statement is found to be untrue, in which case the question is how one defines such an implicit undertaking: is it an implied promise, or is it merely a remedy imposed by law? With more widely conceived warranties (those including an express undertaking to do something if the statement of fact is found to be untrue), it is easier to characterise the warranty as including a promise, though the question remains of whether the promise should be distinguished from the warranty, or whether they are an indissoluble unit.

There seems no obvious objectively correct answer to these definitional questions, and different jurisdictions might conceivably have a narrower or a wider definition of a warranty. Given, however, that it seems theo­ retically possible with a warranty (especially those containing express